IOL for reducing secondary opacification

ABSTRACT

An IOL implantable in an eye comprising an optic having an optical portion for directing light toward the retina of the eye and a cell barrier portion for inhibiting cell growth from the eye in front of or in back of the optical portion. The cell barrier portion circumscribes the optical portion, is incapable of focusing light on the retina and includes an irregularly configured structure, for example, irregular grooves. At least one elongated fixation member is coupled to the optic for use in fixing the optic in the eye.

CROSS-REFERENCE TO RELATED CASE

[0001] This application is a continuation of U.S. Ser. No. 08/919,292,which in turn is a continuation of U.S. Ser. No. 08/703,470, which inturn was a continuation-in-part of U.S. Ser. No. 08/437,656, filed May9, 1995, (U.S. Pat. No. 5,549,670), and of U.S. Ser. No. 08/627,723filed Apr. 2, 1996.

BACKGROUND OF THE INVENTION

[0002] This invention relates to intraocular lenses and in particular tointraocular lenses (IOL's) which reduce secondary opacification.

[0003] An intraocular lens is commonly used to replace the natural lensof the human eye when warranted by medical conditions. It is commonpractice to implant an IOL in a region of the eye known as the capsularbag or posterior capsule.

[0004] One problem that is experienced with many IOL's following theirimplantation is that cells from the eye, particularly lens epithelialcells from the capsular bag, tend to grow on the capsular bag in frontof and/or in back of the optical portion of the IOL. This tends to blockthe optical portion of the IOL and to impair vision.

[0005] A common treatment for this condition is to use a laser todestroy the cells and a central region of the capsular bag. Althoughthis treatment is effective, the laser is expensive and is not availablethroughout the world. There is also cost associated with the lasertreatment as well as some patient inconvenience and risk ofcomplications. Finally, the laser treatment may affect the performanceof some IOL's.

[0006] Davenport U.S. Pat. No. 4,743,254 discloses an IOL which includesglare reducing sections on the opposite sides of an optic. These glarereducing sections are fully or partially opaque and their surfaces arenot smooth. It has been observed that cell migration across the glarereducing sections appears to be reduced. A similar result has beenobserved in a plate IOL in which a plate, which is used as a haptic forfixing the IOL in the eye, surrounds the optic. Specifically cellmigration across the plate, which has a somewhat textured surface,appears to be reduced.

[0007] Kelman U.S. Pat. No. 4,808,181 discloses an IOL including a lensassembly having an anterior surface formation and a posterior surfaceformation. At least a portion of the posterior surface formationconstitutes a planar contact region adapted to seat against theposterior capsule of the eye to permanently anchor the lens assembly.The contact region is provided with a roughened surface area defined bya series of ordered narrow linear depressions extending transverse ofthe plane of the contact region. This patent teaches that these orderednarrow linear depressions accelerate adhesion and enhance anchoring ofthe tissue of the posterior capsule to the lens assembly. This patent isnot concerned with secondary opacification and provides no solution tothis problem.

SUMMARY OF THE INVENTION

[0008] This invention provides an IOL which is believed to solve thesecondary opacification problem discussed above. With this invention, anoptical portion, which is adapted to be placed in the capsular bag of aneye, directs light toward the retina of the eye, and a cell barrierportion circumscribes the optical portion. With this construction, theoptical portion serves the normal function of directing and focusinglight at or near the retina. The cell barrier portion inhibits cellgrowth from the eye, for example, from the capsular bag, in front ofand/or in back of (behind) the optical portion. The optical portion andthe cell barrier portion may be considered as being portions of theoptic.

[0009] The cell barrier portion of the optic circumscribes the opticalportion so as to not leave any path available for the migration of cellsin front of or in back of the optical portion. The cell barrier portionis constructed so as to be incapable of or ineffective in focusing lighton the retina. The cell barrier portion is preferably partially orwholly opaque to eliminate light scattering.

[0010] At least one fixation member, preferably an elongated fixationmember, is coupled to, and preferably extends outwardly from, the opticfor use in fixing the optic in the eye. Viewed from a differentperspective, a structure other than the cell barrier portion is employedfor fixing the optic in the eye. Such structure may include one or morefixation members of various different configurations coupled to theoptic. The fixation members may be separate members attached to theoptic or members which are integral with the optic, and they maycomprise elongated filaments or one or more wider plate or plate-likemembers.

[0011] The cell barrier portion may be of any construction whichperforms the function of inhibiting cell growth from the eye in front ofor in back of the optical portion. In this regard, the cell barrierportion may include an irregularly configured structure or surfacefeature, such as an irregularly roughened or textured surface regionand/or one or more annular grooves which are at least partially definedby irregular surfaces.

[0012] As used herein, the terms “irregular” or “irregularly” refer to athing, for example, an irregularly roughened surface region, or seriesof things, for example, irregular surfaces, which do not have aconsistent order, pattern or configuration. In one embodiment, theseterms refer to a thing or series of things which are substantiallyunordered or which have a pattern or configuration with a significant orsubstantial degree of randomness, or even substantially completerandomness. In one embodiment, the irregularity in accordance with thepresent invention is sufficient to result in the irregularly configuredstructure, present in an otherwise optically clear cell barrier portionto be at least about 50% opaque (that is frosty or hazy), morepreferably at least about 80% opaque and still more preferablysubstantially completely opaque.

[0013] The irregularly configured structure or surface feature of thecell barrier portion preferably has a radial dimension of no more thanabout 2 mm, more preferably no more than about 0.75 mm and still morepreferably no more that about 0.25 mm. If the cell barrier portionincludes an annular groove, the groove preferably has a maximum widthand a maximum depth each no greater than about 0.02 mm. In one preferredconstruction, the cell barrier portion includes at least about 20annular grooves.

[0014] The optic has anterior and posterior faces. The irregularlyconfigured structure, for example, surface roughening or texturingand/or grooves, may be provided on ny surface or surfaces along whichthe cells may migrate and completely circumscribes the optical portion.Preferably, the irregularly configured structure is provided at least onthe posterior face and/or anterior face of the optic in the cell barrierportion.

[0015] The irregularly configured structure or surface feature can beincluded in/on the cell barrier portion using any suitable technique ormethodology. Of course, it is important that this structure or surfacefeature be sufficiently irregular to achieve the desired inhibition ofcell migration or cell growth so that the risk of secondaryopacification is reduced. The technique or methodology chosen to includethis structure or surface feature should take this basic criterion intoaccount. This structure or surface feature can be formed during theinitial formation, for example, the molding, of the cell barrier portionor optic, or can be included after the cell barrier portion or optic isproduced, for example, using a laser, lathe, other mechanical implementand the like. In one particularly useful embodiment, a lathe is employedto form a spiral array of annular grooves defined by irregular surfacesin the cell barrier portion. Cell barrier portions may be processed in amanner similar to the glare reducing sections of Davenport U.S. Pat. No.4,743,254 to yield fully or partially opaque structures the surfaces ofwhich are irregular and not smooth. The disclosure of this patent isincorporated in its entirety herein by reference.

[0016] The cell barrier portion may be integral with the opticalportion, or may be a separate member coupled to the optical portion.Also, the fixation member or members may be integral with the cellbarrier portion and/or the optical portion, or may be a separate elementor elements, e.g., filament or filaments, coupled to the optical portionor the cell barrier portion.

[0017] The invention, together with additional features and advantagesthereof may best be understood by reference to the following descriptiontaken in connection with the accompanying illustrative drawings.

BRIEF DESCRIPTION OF THE DRAWING

[0018]FIG. 1 is a plan view of one form of IOL constructed in accordancewith the teachings of this invention.

[0019]FIG. 1A is an elevational view of the IOL shown in FIG. 1.

[0020]FIG. 2 is an enlarged fragmentary view of the region generallybounded by the arc 2 in Fit 1 and showing a more detailed view of thecell barrier portion of the IOL.

[0021]FIG. 3 is an enlarged fragmentary sectional view taken generallyalong 3-3 of FIG. 2.

[0022]FIG. 4 is an enlarged fragmentary sectional view taken generallyalong line 3-3 of FIG. 2 and showing the growth of cells from thecapsular bag of the eye on only a portion of the cell barrier region.

[0023]FIG. 5 is a plan view of a second form of IOL constructed inaccordance with the teachings of this invention.

[0024]FIG. 6 is an enlarged fragmentary sectional view taken generallyalong line 6-6 of FIG. 5.

[0025]FIG. 7 is a plan view with portions broken away of a third from ofIOL constructed in accordance with the teachings of this invention.

[0026]FIG. 8 is an enlarged fragmentary sectional view taken generallyalong line 8-8 and illustrating another construction of the cell barrierportion.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027]FIGS. 1 and 1A show an IOL 11 which generally comprises an optic13 and fixation members 15 and 17. In this embodiment, the optic 13 maybe considered as including an optical portion 19 for focusing light onor near the retina f the eye and a cell barrier portion 21circumscribing the optical portion and being incapable of focusing lighton the retina. Optical axis 22 passes through the center of optic 13 ina direction generally transverse to the plane of the optic.

[0028] In this embodiment, the optic 13 is circular in plan andbiconvex; however, this is purely illustrative as other configurationsand shapes may be employed. The optic 13 may be constructed of any ofthe commonly employed materials commonly used for rigid optics, such aspolymethylmethacrylate (PMMA), or commonly used for resilientlydeformable optics, such as silicone polymeric materials, acrylicpolymeric materials, hydrogel-forming polymeric materials, mixturesthereof and the like.

[0029] The fixation members 15 and 17 in this embodiment are generallyC-shaped and are integral with the optic 13. However, this is purelyillustrative as the fixation members 15 and 17 may be of otherconfigurations and/or may be separate members affixed to the optic inany of a variety of conventional ways.

[0030] The optic 13 has an anterior face 23, a posterior face 25 and aperipheral edge 27. In this embodiment, the faces 23 and 25 are convexand the peripheral edge 27 is cylindrical, but as indicated above, theseshapes are shown only by way of example.

[0031] The optic 13 is designed to be placed in the capsular bag. Thediameter of the optic 13 may be conventional, and as such, may be about6 mm or less. The optical portion 19 performs the normal function of theoptic of an IOL, i.e. to appropriately focus light at or near theretina. The optical portion 19 may be monofocal or multifocal.

[0032] In this embodiment, the cell barrier portion 21 is integral withthe optical portion 19. The cell barrier portion 21 is incapable offocusing light on the retina of the eye and includes an irregularlyconfigured structure or surface feature effective to inhibit, andpreferably substantially prevent, cell growth radially inwardly acrossthe cell barrier portion. In the embodiment of FIGS. 1-6, the cellbarrier portion 21 includes a concentric array of annular grooves 29each of which is at least partially defined by irregular surfaces.Similar arrays of the grooves 29 are in either the anterior face 23 orthe posterior face 25, or both. Although various different arrangementscan be employed, in this embodiment the grooves 29 are concentric andsubstantially equally spaced apart.

[0033] Without wishing to limit the invention to any particular theoryof operation, it is believed that grooves 29, acts to disrupt orotherwise interfere with the process of eye cell, for example, lensepithelial cell, migration or growth so that the cumulative effect ofthis irregular structure is to significantly reduce, or even eliminate,the migration or growth of cells in front of or in back of the opticalportion 19 after IOL 11 is implanted in the eye. FIG. 4 illustrates thateye cells 30 from the capsular bag 32 do migrate or grow to some extentonto and cover a portion of the cell barrier portion 21. This limitedcell migration is advantageous in at least assisting or facilitating theeffective fixation of IOL 11 in the eye. Thus, the present inventionpreferably provides for such advantageous limited eye lens epithelialcell migration or growth while preventing excessive cell migration orgrowth in front of or in back of the optical portion 19, as shown inFIG. 4.

[0034] Another way of viewing the degree of irregularity of theirregularly configured structure, for example, grooves 29, on cellbarrier portion 21 is opacity. The grooves 29 are sufficiently irregularso that the cell barrier portion 21 is substantially completely opaqueto the transmission of light. When viewed by the naked eye, cell barrierportion 21 is a white or frosty band on the otherwise optically clearoptic 13.

[0035] Preferably, the radial dimension of the cell barrier portion 21is no greater than about 2 mm, and more preferably no greater than 0.25mm.

[0036] In the embodiment shown in FIGS. 1 to 4, the number of grooves 29is about 50 to about 100. In order to obtain an advantageous degree ofcell migration inhibition, it is preferred that the number of groovesincluded in cell barrier portion 2 be at least about 20, although fewergrooves can provide some useful benefits.

[0037] The grooves 29 are located wherever it is desired to inhibit cellmigration. In the present embodiment, the grooves 29 are placed on boththe anterior face 23 and the posterior face 25 so that the cell barrierportion 21 is on both faces of the optic 13. However, the cell barrierportion can be eliminated from a particular face if it is determinedthat cell migration in front of that face is not likely to occur.

[0038] The IOL 11 can be implanted in the capsular bag of the eye inaccordance with conventional techniques. When so implanted, the cellbarrier portion 21 defines a radially relatively narrow annular barrierfor inhibiting cell growth radially inwardly in front of or in back ofthe optical portion 19 where the cells could cause secondaryopacification.

[0039] The present invention is applicable to IOLs including a hard orrigid optic, such as the optics made from PMMA, and those which includea foldable or deformable optic, such as optics comprising siliconepolymeric materials, other acrylic polymeric materials, hydrogel-formingpolymeric materials, such as polyhydroxyethylmethacrylate (poly HEMA),and the like. Such foldable/deformable optics are particularlyadvantageous since they can be inserted into the eye through a smallincision. The fixation members 15 and 17, are flexible and strandlike orfilaments so that they can be easily inserted into the eye. The fixationmembers 15 and 17 can be formed integrally with the optic 13 or can beseparately coupled to the optic.

[0040]FIGS. 5 and 6 show an IOL 11 a which is identical to the IOL 11 inall respects not shown or described herein. Portions of the IOL 11 acorresponding to portions of the IOL 11 are designated by correspondingreference numerals followed by the letter a.

[0041] The only difference between the IOL's 11 and 11 a is that in theIOL 11 a the grooves 29 are replaced with an irregularly roughened ortextured surface 31. The cell barrier portion 21 a, in particular theroughened or textured surface 31, is sufficiently irregular as to be atleast partially, and preferably substantially completely, opaque to thetransmission of light. This not only provides cell migration inhibition,but also avoids glare from the interaction of light with the cellbarrier portion 21 a. The textured surface 31 may be textured orroughened in any of a variety of ways including machining as with alathe, chemical etching, abrading or the like. If the optic 13 a ismolded, as for example when it is constructed of silicone polymericmaterial or other soft foldable material, the texturing or roughening ofthe textured surface 31 may be imparted by the mold.

[0042] The degree of irregularity of the roughening of the surface 31should be sufficient to enable the textured surface to perform theinhibition of cell migration function.

[0043]FIGS. 7 and 8 show an IOL 11 b which is identical to the IOL 11 inall respects not shown or described herein. Portions of the IOL 11 bcorresponding to portions of the IOL 11 are designated by correspondingreference numerals follows by the letter b.

[0044] There are two primary differences between the IOL's lib and 11.First, in the IOL 11 b, the fixation members 15 b and 17 b are separatestrands or filaments which are attached to the optic 13 b in an suitableconventional manner. Secondly, the cell barrier portion 21 b is in theform of a separate member coupled to the optical portion 19 b.

[0045] In this embodiment, the cell barrier 21 b includes spaced legs 33joined by a web 35. The legs 33 engage the faces 23 b and 25 b,respectively, and the web 35 confronts and engages the peripheral edge27 b. The cell barrier portion 21 b is annular and extends completelyaround the optical portion 19 b and is mounted on the optical portion ina manner similar to a tire. The cell barrier portion 21 b may have aradial width of up to about 2 mm or about 1 mm, for example, about 0.25mm.

[0046] While this invention has been described with respect to variousspecific examples and embodiments, it is to be understood that theinvention is not limited thereto and that it can be variously practicedwithin the scope of the following claims.

What is claimed is:
 1. An intraocular lens implantable in an eyecomprising: an optical portion adapted for placement in the capsular bagof the eye and for directing light toward the retina of the eye; a cellbarrier portion for inhibiting cell growth from the eye in front of orin back of said optical portion; said cell barrier portioncircumscribing said optical portion, including an irregularly configuredstructure and being incapable of focusing light on the retina; and atleast one elongated fixation member coupled to said optical portion foruse in fixing said intraocular lens in the eye.
 2. An intraocular lensimplantable in an eye comprising: an optic, adapted for placement in thecapsular bag of the eye, having an optical portion for directing lighttoward the retina of the eye and a cell barrier portion for inhibitingcell growth from the eye in front of or in back of the optical portion;said cell barrier portion circumscribing the optical portion, includingan irregularly configured structure and being incapable of focusinglight of the retina; and a member other than the cell barrier portionfor fixing the optic in the eye.